Monte Carlo simulation of secondary electron emission from amorphous carbon-coated copper surface with rectangular grooves

Abstract

Secondary electron emission (SEE) critically limits the performance of high-power microwave components and particle accelerators. Amorphous carbon (a-C) films featuring a low secondary electron yield (SEY) and surface grooves offer promising applications for suppressing the SEE effects. However, the efficiency of SEE suppression and the underlying microscopic mechanisms remain subjects of debate. This paper employs the Monte Carlo method to develop a novel electron scattering and an SEE model for copper surfaces coated with a-C films and patterned with rectangular grooves. The model accurately simulates electron transport within the film and substrate, explicitly accounting for the influences of the film/substrate interface energy barrier and the groove walls on electron scattering trajectories. Results demonstrate that increasing the a-C film thickness from 0 to 5 nm reduces the maximum SEY from 1.18 to 0.82. The SEE suppression effect is significantly enhanced on grooved a-C surfaces. Specifically, with a groove depth of 30 nm and a film thickness of 5 nm, the maximum SEY reaches a minimum value of 0.47. These findings provide important insights into the mechanism by which grooves and a-C films suppress SEE and offer practical guidance for designing high-performance, low-SEY surfaces for the next generation of high-power devices.